The Methodology/Data Management Core is critically important to the success of the Northwestern University MCRC. The centralized availability of expertise in database and study form development; data monitoring, data entry and retrieval; and the various analytic techniques used to test hypotheses and control for potential confounders are essential resources for both established and new investigators. Recogniz ng that newer analytic techniques have become available and more accepted in the medical literature, this proposal continues the expansion of our work in clinical epidemiology and health services research previously implemented. Given this Center's emphasis on longitudinal research, experts in advanced statistical techniques [generalized estimating equations (GEE), discrete survival time regression analysis, as well as meta-analysis and classification and regression trees (CART)], economics, decision analysis, clinical epidemiology, behavioral science, and genomics are included as Core investigators. New expertise in patient reported outcome measures, diet/physical activity measurement, and bioinformatics is now included. The Core provides essential methodological, data integrity, and safety plan functions for all 3 proposed MCRC projects. In addition, this Core will continue to serve the arthritis research community more broadly by providing an environment that encourages collaboration between Core methodologists and staff and MCRC-affiliated faculty and trainees on every clinical, epidemiologic, and health services arthritis reseai'ch project proposed and implemented at Northwestern. Through its active relationships with the Northwestern University Feinberg School of Medicine's (NU-FSM) Departments of Preventive Medicine, Physical Medicine & Rehabilitation, and Medical Social Sciences, the Institute for Healthcare Studies, and the NU Clinical and Translational Science (NUCATS) Institute, the MCRC Methodology/Data Management Core is able to draw on the relevant talent and expertise of a diverse University community to not only help solve the research challenges of projects pertaining to a variety of rheumatologic conditions of interest to NIAMS (e.g., osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, scleroderma), but also to promote and sustain interdisciplinary team research in these fields. The Core is led by a seasoned rheumatology investigator and includes both senior and junior faculty methodologists as well as experienced statistical analysts and programmers/database managers. Over the years of Northwestern's NIAMS P60, Core operational procedures have evolved to maximize cost-effectiveness and quality of educational offerings.